Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.wicket.util.template; import java.io.IOException; import java.util.Locale; import java.util.Map; import java.util.Objects; import org.apache.wicket.Application; import org.apache.wicket.util.io.Streams; import org.apache.wicket.util.lang.Packages; import org.apache.wicket.util.resource.IResourceStream; import org.apache.wicket.util.resource.ResourceStreamNotFoundException; import org.apache.wicket.core.util.resource.locator.ResourceStreamLocator; import org.apache.wicket.util.string.interpolator.MapVariableInterpolator; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * A <code>String</code> resource that can be appended to. * * @author Eelco Hillenius * @since 1.2.6 */ public class PackageTextTemplate extends TextTemplate { /** log. */ private static final Logger log = LoggerFactory.getLogger(PackageTextTemplate.class); private static final long serialVersionUID = 1L; /** The content type used if not provided in the constructor */ public static final String DEFAULT_CONTENT_TYPE = "text"; /** The encoding used if not provided in the constructor */ public static final String DEFAULT_ENCODING = null; /** contents */ private final StringBuilder buffer = new StringBuilder(); private final Class<?> scope; private final String fileName; private String encoding; /** * Constructor. * * @param clazz * the <code>Class</code> to be used for retrieving the classloader for loading the * <code>PackagedTextTemplate</code> * @param fileName * the name of the file, relative to the <code>clazz</code> position */ public PackageTextTemplate(final Class<?> clazz, final String fileName) { this(clazz, fileName, DEFAULT_CONTENT_TYPE); } /** * Constructor. * * @param clazz * the <code>Class</code> to be used for retrieving the classloader for loading the * <code>PackagedTextTemplate</code> * @param fileName * the name of the file, relative to the <code>clazz</code> position * @param contentType * the mime type of this resource, such as "<code>image/jpeg</code>" or " * <code>text/html</code>" */ public PackageTextTemplate(final Class<?> clazz, final String fileName, final String contentType) { this(clazz, fileName, contentType, DEFAULT_ENCODING); } /** * Constructor. * * @param clazz * the <code>Class</code> to be used for retrieving the classloader for loading the * <code>PackagedTextTemplate</code> * @param fileName * the name of the file, relative to the <code>clazz</code> position * @param contentType * the mime type of this resource, such as "<code>image/jpeg</code>" or " * <code>text/html</code>" * @param encoding * the file's encoding, for example, "<code>UTF-8</code>" */ public PackageTextTemplate(final Class<?> clazz, final String fileName, final String contentType, final String encoding) { this(clazz, fileName, null, null, null, contentType, encoding); } /** * Constructor. * * @param clazz * the <code>Class</code> to be used for retrieving the classloader for loading the * <code>PackagedTextTemplate</code> * @param fileName * the name of the file, relative to the <code>clazz</code> position * @param style * Any resource style, such as a skin style (see {@link org.apache.wicket.Session}) * @param variation * The template's variation (of the style) * @param locale * The locale of the resource to load * @param contentType * the mime type of this resource, such as "<code>image/jpeg</code>" or " * <code>text/html</code>" * @param encoding * the file's encoding, for example, "<code>UTF-8</code>" */ public PackageTextTemplate(final Class<?> clazz, final String fileName, final String style, final String variation, final Locale locale, final String contentType, final String encoding) { super(contentType); this.scope = clazz; this.fileName = fileName; this.encoding = encoding; setStyle(style); setVariation(variation); setLocale(locale); } @Override public void setStyle(String style) { if (Objects.equals(style, getStyle()) == false) { buffer.setLength(0); } super.setStyle(style); } @Override public void setLocale(Locale locale) { if (Objects.equals(locale, getLocale()) == false) { buffer.setLength(0); } super.setLocale(locale); } @Override public void setVariation(String variation) { if (Objects.equals(variation, getVariation()) == false) { buffer.setLength(0); } super.setVariation(variation); } public void setEncoding(String encoding) { if (Objects.equals(encoding, this.encoding) == false) { buffer.setLength(0); } this.encoding = encoding == null ? DEFAULT_ENCODING : encoding; } /** * Loads the template if it is not loaded yet */ private void load() { if (buffer.length() == 0) { String path = Packages.absolutePath(scope, fileName); Application app = Application.get(); // first try default class loading locator to find the resource IResourceStream stream = app.getResourceSettings().getResourceStreamLocator().locate(scope, path, getStyle(), getVariation(), getLocale(), null, false); if (stream == null) { // if the default locator didn't find the resource then fallback stream = new ResourceStreamLocator().locate(scope, path, getStyle(), getVariation(), getLocale(), null, false); } if (stream == null) { throw new IllegalArgumentException( "resource " + fileName + " not found for scope " + scope + " (path = " + path + ")"); } setLastModified(stream.lastModifiedTime()); try { if (encoding != null) { buffer.append(Streams.readString(stream.getInputStream(), encoding)); } else { buffer.append(Streams.readString(stream.getInputStream())); } } catch (IOException e) { throw new RuntimeException(e); } catch (ResourceStreamNotFoundException e) { throw new RuntimeException(e); } finally { try { stream.close(); } catch (IOException e) { log.error(e.getMessage(), e); } } } } /** * @see org.apache.wicket.util.resource.AbstractStringResourceStream#getString() */ @Override public String getString() { load(); return buffer.toString(); } /** * Interpolates a <code>Map</code> of variables with the content and replaces the content with * the result. Variables are denoted in the <code>String</code> by the * <code>syntax ${variableName}</code>. The contents will be altered by replacing each variable * of the form <code>${variableName}</code> with the value returned by * <code>variables.getValue("variableName")</code>. * <p> * WARNING: there is no going back to the original contents after the interpolation is done. If * you need to do different interpolations on the same original contents, use the method * {@link #asString(Map)} instead. * </p> * * @param variables * a <code>Map</code> of variables to interpolate * @return this for chaining */ @Override public final TextTemplate interpolate(Map<String, ?> variables) { if (variables != null) { load(); String result = new MapVariableInterpolator(buffer.toString(), variables).toString(); buffer.setLength(0); buffer.append(result); } return this; } }